222 UFB OF hygrometer shows a gradually Increasing moisture, the stars are sometimes veiled by a slight mist, their light is not steady, and they are occasionally seen to sparkle about twenty degrees above the horizon. The breeze blows less violently, and there is often a total wind calmness. South-south-east of the horizon the clouds gather, they seem like distant moimtaiiis with inaccurately defined outlines; they are sometimes seen to quit the horizon, and scud through the sky with a speed quite inconsistent with the weakness of the wind in the lower atmosphere. Towards the end of March., the southern region of the atmosphere is lighted by small electric explosions; they are phosphorescent sparks, limited to a single group of mist. Now, from time to time, south-west winds occur., lasting some hours, and are the sure signs of the approach of the rainy season, which begins towards the end of April in the Orinocco district. The sky then begins to be clouded, the clear blue disappears, and a uniform grey colour takes its place. At the same time, the warmth of the atmosphere in- creases, and not only clouds, but dense mists, cover the vault of heaven. The howling monkeys make themselves heard several hours before break of day; the atmospheric electricity, which, during the dry season from December to March, had nearly always averaged 1-72 liaes of the voltaic electrometer during the day, becomes extremely variable, being sometimes 03 sometimes 3A lines. The rainy season is also the season of thunder- storms. The storm commences two hours after the - passage of the sun through the meridian., a short time after the period when the heat has reached its maxi- mum. The thunder is rarely heard in, the night or in the morning; but these thunder-storms are alto- gether only confined to certain river districts having a peculiar climate.